Cardboard or paper containers or boxes of various shapes and sizes are commonly used to contain consumer products, foods, cosmetics and other merchandise. Such boxes and containers are bio-degradable, easily disposed of and may be manufactured in accord with practically any specification relatively inexpensively.
Over the years, computerized technology has evolved wherein the process of generating boxes or die cut forms from sheets of paper or cardboard stock is done automatically by controlled machine systems without the need for intensive labor or human operators. It is also common for the manufactured planar box blanks to be assembled, filled with merchandise and sealed automatically by machine.
Too, the advent of computer and CAD technology now enables designers to compile optimum layouts of a plurality of die cut forms on a single sheet for multiple scoring and stamping during the course of the manufacturing process. In addition, computer technology, combined with attendant laser technology, has enabled box manufacturers to utilize highly accurate cutting and creasing dies for producing a planar sheet of diecut blanks and also, to produce male and female blanking dies used to automatically separate the die cut or stamped forms from the intervening web or waste portion of the sheet. Automatic blanking, in particular, results in a tremendous cost savings compared to the identical operation when performed by laborers using manual blanking means.
The current technology and the known prior art includes automatic systems or presses that feed large sheets of paper for cutting and creasing of blanks and also, for automatically stripping the excess paper from the stamped sheet, leaving a flexible thin webbing supporting the various rows of stamped forms. The known prior art also contemplates the use of a male and female combination blanking die for automatically separating the planar forms from the flexible web. In short, the male die, effectively through the use of a blanking member, pushes each of the box blanks through the web and supporting female die blanking holes. The thin web typically remains on the face of the female die while the separated blanks are pushed through the blanking holes into a stack below the female blanking die.
For speed and efficiency, the prior art also contemplates the use of a traveling feed bar and grippers to "pull" a sheet through the various stations of the process on a continuous chain drive or other mechanism thereby automatically feeding the sheet from station to station. Similarly, in most applications, the remaining flexible web on the face of the female die after blanking is also pulled away through the use of the traveling bar and grippers into a waste container or other receptacle at the end of the machine.
A problem not yet solved by the prior art, however, involves the remaining thin web typically found on the face of the female die after separation of the box blanks through the use of the male blanking member. In particular, if forms in excess of a specified width are blanked, the remaining web is typically extremely flexible and non-supporting. Accordingly, as the web is pulled from the female blanking die face through the use of the grippers and traveling bar, the inner web portion has a tendency to sag down and become entangled or severed by the edges of the female blanking die. This can cause the automatic blanking operation and feeding of sheets to become inefficient and prone to jamming and breakdown. Accordingly, automatic blanking is limited in the prior art to blanks of less than a predetermined width and with a certain web support strength, in turn limiting the size of die cut paper forms that can be cut on a single sheet which can be produced if the more efficient blanking operation is to be used to separate the die cut blanks from the web.
The present invention solves the problem of blanking forms of significant width through the use of strategically and flexibly placed outfeed lifter ramps which, in effect, serve to internally support the thin web produced after blanking is complete while permitting the sheet, prior to blanking, to be placed firmly on the female cutting die for separation.
Accordingly, the present invention contemplates use of automatic blanking, and the concomitant savings in labor and time, with sheets of die cut forms of practically any width and configuration.